Refrigerant holdover package



0, 1957 J. c. SHEPHERD 2,803,115

REFRIGERANT nowovaa PACKAGE Filed July 17, 1953 I5 Sheets-Sheet 1 srARcH#07 WA TE]? 5:. wmv

INVENTOR- JOHN G. SHEPHERD ATTORNEY WM h 1957 J, c. SHEPHERD 2,803,115

REFRIGERANT nowovaa PACKAGE Filed July 17,1953 3 Sheets-Sheet 2 Eig-.ZU.

INVENTOR. JOHN C- SHEPHERD ATTORNEY Aug. 20, 1957 J. c. SHEPHERD2,803,115

REFRIGERANT HOLDOVER PACKAGE Filed July 17. 1953 3 Sheets-Sheet 3UINVENTOR. E W

JOHN a. SHEPHERD A TTORNEY United States Patent REFRIGERANT HOLDOVERPACKAGE John C. Shepherd, Monrovia, Calif.

Application July 17, 1953, Serial No. 368,748

Claims. (Cl. 62-1) This invention relates to an improved refrigerantwhich does not leak water after its temperature rises above the eutecticpoint. More specifically this invention relates to a refrigerantholdover package which is suitable for re-use, i. e., the refrigerantmay be repeatedly frozen and thawed.

For many purposes, water ice is an undesirable refrigerant solelybecause it melts into water at the comparatively low temperature of 32F. Once it turns to water, it flows away from the goods so that it is nolonger present to refrigerate them; still worse, it often spoils thegoods being refrigerated and damages or destroys the shipping containerin which the goods are packed. Except for this property of melting,water ice is an excellent refrigerant, because it has very high specificheat and a very high heat of fusion.

I have solved the problem caused by the melting of water ice and havedevised a refrigerant that incorporates water, along with its attendantadvantages, but does not liquefy when its temperature exceeds itsfreezing or eutectic" point; i. e. that temperature where a quantity ofheat energy is transferred without any resultant change in temperature,due to a change of state. The quantity of heat consumed during thischange in state is commonly known as the heat of fusion."

Water cannot be packaged satisfactorily for use as a refrigerant,because, if the container is ruptured, the water will flow out when itis melted. Various materials have been employed in attempts to holdwater. For example, a. packaged refrigerant utilizing sawdust and water,has been proposed, but if the container was ruptured, or if it wasprovided with perforations in order to permit the sawdust to absorb thewater, then the sawdust would leak water, especially when it wassubjected to any pressure. Therefore, packaged refrigerants hadheretofore proved unsuccessful, because once there was a hole throughthe package, water would leak out.

In other patent applications, Serial No. 363,155, filed June 22, 1953,and Serial No. 363,186, filed June 22, 1953, I have presented a greatlyimproved refrigerant utilizing nonleaking gels. These gels are usuallycomposed of starch modified by borax and sometimes by an aldehyde, and,in some cases, with materials which modify the eutectic point (e. g.soluble mineral salts). Although these gels have provided a very goodsolution to the problems mentioned above, their use led to certain otherproblems. While they did not leak water when they thawed, and while theylasted a considerable length of time when made according to certainformulas, their life was limited by certain factors. For one thing, theytended to dry out when exposed to surrounding dry air, and in time thisdrying action would render the gel useless, long before it became anxerogel. At other times, in moist air, the coldness of the gel in itsfrozen stage caused condensation from the atmosphere, and this condensedmoisture would often react with the gel to weaken its structure andsometimes break it down by making it too watery. Another difficulty withstarch gels in certain uses, was that they tended to add water to goodswhich were water-absorbent, simply by contact.

Another difficulty with the gel refrigerants formerly used was thattheir shape would break down and change. Layers which were better keptseparate would coalesce into larger pieces than were desirable. Shapescorresponding to the spaces between the goods would be formed, andsometimes had to be cut apart before they could be used. Furthermore,the gels would often stick to the goods or their containers, withresultant damage to either the goods or the gel or both. These gels alsotended to get contaminated by foreign matter in the air or theenvironment. A further problem was that the gels were difficult tohandle, due to the fact that each piece of gel was held together only byits own internal structure and also due to its tendency to coalesce withother pieces of gel, as well as the other effects mentioned above.

I have solved the problems which have been explained above, by providinga packaged gel refrigerant. Lest it be assumed that gel in a package islike any other type of goods in a package, it should be explained thatrather astonishing and unexpected results flow from my combination,because of a novel coaction between the gel and the package. In thefirst place, the gel will not leak from a punctured package as willwater, which will leak whether or not it be combined with sawdust oranother absorbing agent. In the second place, the gel will seal theleak. If the package containing my improved gel is punctured or cut-andthe cuts or punctures may be very large in areathe gel itself will sealthe holes against leakage and prevent damage to the bulk of the gel byhaving a small portion dry out. As a result of this co action, thepackaged gel is self-sealing.

The Package obviously aids the handling of the gel and enables it tomaintain its original shape. Also the packaging adds considerably to thelife of the gel by cutting down the exposure to air, the contamination,and the tendency to dehydrate or to absorb water. More important, whenmoisture is condensed from the air by the gel refrigerant, the moistureforms on the outside of the package rather than on the gel itself.Furthermore, the package itself prevents the sticking that occurredbetween the gel and other surfaces; the only sticking that the gel cando is in its own package where such sticking is not desirable.

Other advantages of the invention will appear in the followingdescription, given in accordance with 35 U. S. C. 112.

In the drawings:

Fig. l is a view in elevation, somewhat diagrammatic in nature, of awaterproof transparent container being filled with a starch slurry andhot water having borax dissolved therein, to form therein a stablenon-leaking gel, in accordance with the present invention.

Fig. 2 is a view in perspective, also somewhat diagrammatic in nature,showing the container of Fig. 1 being sealed at its open end.

Fig. 3 is a view in perspective, somewhat diagrammatic in nature,showing the container of Figs. 1 and 2 being pressed to distribute thematerial therein evenly and being punctured to let out air entrappedtherein.

Fig. 4 is a view in perspective of the completed packaged refrigerant.

Fig. 5 is an enlarged diagrammatic view in section illustrating how thegel seals an opening accidentally made through the walls of itscontainer.

Fig. 6 is a view in elevation of a modified form of container.

Fig. 7 is a view in section taken along the line 7-7 in Fig. 8 is a viewsimilar to Fig. 7 showing the closed position of the container opening.

Fig. 9 is a view taken along the line 99 of Fig. 6.

Fig. 10 is a view in elevation of a portion of a container having amodified form of opening.

Fig. 11 is a view taken along the line 11-11 in Fig. 10, with theopening shown in its open position.

Fig. 12 is a view similar to Fig. 11 showing the opening closed.

Fig. 13 is a view in section taken along the line 1313 of Fig. 10.

Fig. 14 is a view in perspective of another modified form of theinvention.

Fig. 15 is a view in perspective of still another modified form of theinvention.

Fig. 16 is a view in perspective showing an early step in a method formaking another modified form of package. A block of gel has been spreadout uniformly on a sheet of wrapping material.

Fig. 17 is a view in perspective showing the sheet of Fig. 16 foldedover with the edges open.

Fig. 18 is a view in section taken along the line 18-18 of Fig. 17, withthe edges sealed.

Fig. 19 is a view in perspective of a slab of gel on a fiat containersheet.

Fig. 20 is a view showing the slab of Fig. 19 rolled up into ajelly-roll-like shape, with the ends open.

Fig. 21 is a view in elevation of the Fig. 20 container with its endsclosed.

All forms of the invention comprise a package made up of gel and acontainer.

The gel may be a starch-borax gel of the type shown in theaforementioned copending applications, and it may have the followingproportions:

Example 1 Starch 100 parts. Water Between 300 and 2,000 parts. BoraxBetween 13 and 100 parts.

Example 2 Starch 100 parts. Water 300 to 2,000 parts. Borax 3 to 100parts. Paraformaldehyde /2 to 100 parts.

The gels shown above may be made by adding the borax and ungelatinizedstarch to relatively cool water and heating the mixture to about theboiling point, until it gelatinizes, or the gels may be made by anyother suitable method. Since formulas and methods are given in the otherpatent applications referred to and since this application relates tocombination of the gel and the package, detailed formulas areunnecessary here. In addition to starch gels, the gel-like substancesmade by mixing finely powdered bentonite clay with cold water may beused for some uses. So may the water mixture with cellulose gum or CMC,which is a sodium salt of carboxymethylcellulose. So may gels made frompre-gelatinized starch. However, the gel or gellike substance must beone that is capable of the selfsealing action which has been described,or full advantage cannot be taken of the invention.

Certain features of the package depend upon the use to which it is to beput. It can be made almost any shape, and the package serves to retainthe gel in selected shape.

The material from which the container is made is preferably flexible andwaterproof, especially when the gel is to be reusable. In such instancesit may comprise polyethylene film, rubber, rubberized canvas, waterproofcellophane, vinyl plastic film, etc. Transparent containers areespecially good for many uses, as observation of the gel becomespossible. Where the gel is to be used only once, and where the problemis simply that of making the handling easier, and avoiding sticking uponcontact with the goods and related problems, the container may be madefrom a relatively inexpensive type of waterproof cellophane and may beleft open at one end, so long as the gel does not come in contact withthe goods. For more permanent use, the more rugged materials referred toshould be used, and the package should be sealed tight. The seal may bea hermetic one, as by welding the plastic film together or may be amechanical one.

Where a sealed package is to be used in order to produce a longerlasting product, it is possible to manufacture the gel in the container.This may be done by mixing cold water with borax and powderedpregelatinized starch or with bentonite or with cellulose gum, directlyin the package. Or this may be done, as in Fig. l, where hot water,preferably containing dissolved borax, is mixed in the container 10 witha warm slurry of water and ungelatinized starch, preferably containingformaldehyde. The container 10 may simply be filled with the gelatinousliquid 11 to a predetermined level, by properly adjusting the flow ofthe slurry by means of the valve 12, to the flow of the hot water,through the valve 13. The valve 14 may be used to cut off the flow ofthe mixture.

As shown in Fig. 2, the container 10 may be sealed along the top seam15, by means of an electrical plastic welder 16, for example. For someuses sealing is not necessary, but the life may be greatly prolongedthereby.

While the gel 11 is still warm, the package may be placed in a press 17as in Fig. 3. There the final shape of the gel is formed, whether it bea slab or a cylinder, or whatever. Air trapped inside the container maybe let out by making a small puncture 18 by a needle 19, and thepressure will force the air out. The drying of the gel 11 seals thepuncture 18, as shown in Fig. 5.

Fig. 4 shows a slab type of package 20 made by the above process, wherethe gel 11 is encased in a container 10 of transparent polyethylene orsome similar material. The flat form of this slab 20 is very useful forplacing under or over such containers as frozen food boxes. The slab 20may also be placed inside such containers. The slab 20 may be used overand over repeatedly and is practically permanent.

As Fig. 5 shows, when a puncture 18 occurs in the container 10, the gel11 at that point becomes somewhat dehydrated over a very small surface,and forms a crusted area that prevents any breakdown of the bulk of thegel or any absorption of water by the gel 11 or loss of water from it.Due to the use of the gel 11 in the container 10, no material will oozeout of even a large hole or slit, even if the package is under aconsiderable pressure, unless the pressure be applied very unevenly, andthen only when the pressure is far larger than that to which thecontainer is normally exposed.

A modified form of container 30 is shown in Fig. 6. Here the edges 31are all closed or seamed, and an opening 32 is provided for filling thecontainer 30 with the gel 11. This opening 30 is a type that can besealed substantially air tight by hand, but can be opened at any time byhand. It includes a flap 33 having a pair of parallel beads 34, 35 witha groove 36 between them. A tongue 37 on the other fiap 38 locks intothe groove 36, the enlarged, flared shape and the elasticity of thematerial helping obtain this result. Figs. 7, 8 and 9 show thisstructure in detail.

A similar result is obtained in the container 40, where a zipper 41closes the opening 42 by leading the tongue 43 into the groove 44between the two heads 45, 46.

Fig. 14 shows a package that is cylindrical, and has seamed ends 51hermetically sealed.

Fig. 15 shows a cylindrical package 55 containing the same gel 11 as theother packages, with the ends 56 of the container gathered and held byfusing them together, by tying, or by a ring 57.

Figs. 1618 show an alternative method of obtaining a slab-like package,similar generally to the package 20. A flat sheet 60 of flexiblewrapping material (e. g. wax paper or polyethylene or rubber) is placedon a fiat surface, and a slab of gel 61 is placed thereon, the slabbeing spaced in from the edges and from the midpoint of the sheet 60.The slab 61 may have been cut or sliced from a large bulk of gel or maybe formed then. Then the sheet 60 is folded over at 62 on top of the gel61 and pressed down evenly. This sandwich 63 may then be used as acovered refrigerant, and is a very practical means of handling andapplying the refrigerant in many commercial applications, especially insizes of about 12" x 16" x 1. However, a longer lasting gel, and onewhich may contain more water per solids (making it cheaper and also abetter refrigerant), can be made by sealing the edges, as with freezertape 64, or by welding the plastic.

Figs. 19 to 21 show another way to utilize the same basic idea in acylindrical package. Here a flat sheet 70 has a slab 71 of gel laidthereon. Then the sheet 70 and gel 71 are rolled up together like ajelly roll to form the cylinder 72 of Fig. 20. This cylindricalrefrigerant will hold its shape very well. For greater permanence, theends 73 may be gathered together and tied with :a string 74 or welded orotherwise fastened together.

To those skilled in the art to which this invention relates, manychanges in construction and widely differing embodiments andapplications of the invention will suggest themselves without departingfrom the spirit and scope of the invention. The disclosures and thedescription herein are purely illustrative and are not intended to be inany sense limiting.

I claim:

1. A refrigerant holdever package for use as a semipermanent refrigerantwhich can be repeatedly frozen and thawed, consisting essentially of agel chosen from the class consisting of the gels of starch, bentonite,and cellulose gum, said gel including water as the main ingredient, saidgel being encased in a sealed waterproof container, said gel serving toseal punctures made in said container.

2. A process for making a shaped refrigerant article, comprising thesteps of filling a container partially full of water and a substancethat reacts with said water to form a generally water-tight gel, sealingthe resulting gel in said container, exerting pressure on the containerto shape said gel, and puncturing the container while it is underpressure to eliminate entrapped air, said gel operating to seal thepuncture.

3. A method for making a shaped refrigerant article, comprising thesteps of filling a container with a hot gel which on cooling will besubstantially water-tight, sealing said container shut, applyingpressure to shape the gel in the container and drive contained air to apredetermined locus, puncturing said container to let said contained airout, and cooling said gel in its container.

4. A method for making a shaped, non-leaking, refrigerant article,comprising the steps of introducing simultaneously into a containerwater and a water-gelling substance chosen from the group consisting ofstarch, bentonite, and cellulose gum, mixing them to form a gel, andshaping said gel under pressure in said container.

5. A refrigerant holdover package for use as a semipermanent refrigerantwhich can be repeatedly frozen and thawed, consisting essentially of agel composed essentially of starch, borax, and water in proportions ofbetween 300 and 2,000 parts of water and between 13 and parts of boraxper 100 parts of starch, said gel being encased in a sealed Water-proofcontainer, said gel serving to seal punctures made in said container.

6. A refrigerant holdover package for use as a semipermanent refrigerantwhich can be repeatedly frozen and thawed, consisting essentially of agel composed essentially of starch, water, borax, and paraformaldehyde,in the approximate proportions of between 300 and 2,000 parts of water,between 3 and 100 parts of borax, and between /2 and 100 parts ofparaformaldehyde, per 100 parts of starch, said gel being encased in asealed waterproof container, said gel serving to seal punctures made insaid container.

7. A process for making a shaped refrigerant article comprising thesteps of filling a flexible water-proof container with gelling mixtureof water, borax, and starch in the proportions of between about 300 and2,000 parts of water and between about 13 and 100 parts of borax per 100parts of starch, sealing the resulting gel in said container, exertingpressure on the container to shape said gel, and puncturing thecontainer while it is under pressure to eliminate entrapped air, saidgel acting to seal the puncture.

8. A process for making a shaped refrigerant article comprising thesteps of filling a flexible water-proof container with a gelling mixtureof water, borax, paraformaldehyde, and starch in the approximateproportions of between 300 and 2,000 parts of water, between 3 and 100parts of borax, and between fa and 100 parts of paraformaldehyde, per100 parts of starch, sealing said container shut, applying pressure toshape the gel in the container and drive the contained air to apredetermined locus, puncturing said container to let said contained airout, the gel sealing the puncture, and cooling the gel in saidcontainer.

9. The refrigerant holdover package as set forth in claim 1 wherein saidpackage is of generally cylindrical sausage configuration.

10. The refrigerant holdover package as set forth in claim 1 whereinsaid package is a roll of frozen gel and the container is sheetmaterial, rolled like a jelly roll.

References Cited in the file of this patent UNITED STATES PATENTS1,889,882 Woods Dec. 6. 1932 1,988,058 Traller Jan. 15, 1935 2,154,933Hadsell Apr. 18, 1939 2,210,946 Moore Aug. 13, 1940 2,490,047 Gilchristet al. Dec. 6, 1949 2,515,582 Beckwith et a1. July 18, 1950 2,574,763Sears Nov. 13, 1951

1. A REFRIGERANT HOLDOVER PACKAGE FOR USE AS A SEMIPERMANENT REFRIGERANTWHICH CAN BE REPEATEDLY FROZEN AND THAWED, CONSISTING ESSENTIALLY OF AGEL CHOSEN FROM THE CLASS CONSISTING OF THE GELS OF STARCH, BENTOMITES,AND CELLULOSE GUM, SAID GEL INCLUDING WATER AS THE MAIN INGREDIENT, SAIDGEL BEING ENCASED IN A SEALED WATERPROOF CONTAINER, SAID GEL SERVING TOSEAL PUNCTURES MADE IN SAID CONTAINER.